The inductive charging system includes at least one induction coil and the portable electronic device includes at least one receiving coil or induced coil. The induction coil or coils are electrically isolated from the receiving coil or coils. The energy is transferred by electromagnetic coupling between the induction coil and the receiving coil, which creates an induced current in the receiving coil used to charge the battery or batteries of the portable electronic device.
The portable electronic device is advantageously a mobile phone but may also be, without this being restrictive, a personal assistant, an audio and/or video player, a graphics tablet or a navigation device.
The charging system comprises a flat receiving face beneath which the induction coil or coils are placed. The portable electronic device is placed on this receiving face, in general the back of the device against the receiving face. As the charging system is intended to perform the inductive charging of a portable electronic device from among a selection of portable electronic devices of different dimensions and therefore to be universal for this selection, the stand is relatively flat and does not take the shape of a cradle specifically dedicated to one type of portable electronic device.
The efficiency of the electromagnetic coupling between the induction coil and the inductive receiving coil depends on the correct alignment of same and a small distance that separates them. The fact that the receiving face formed by the charging system does not have a cradle means that the alignment between the induction and receiving coils is not mechanically ensured.
There are principally three systems of inductive charging of a portable electronic device of the mobile phone type that can be used in a motor vehicle.
The first inductive charging system includes a stand having elements for locking the electronic device in position for centering it in a charging position with respect to a single inductive coil that the system comprises.
The second charging system is a system with multiple induction coils for charging the battery of the portable electronic device regardless of its position on the system stand.
The third charging system includes an induction coil that can move in order to be positioned with respect to a receiving coil for the electronic device once it has been placed on the stand provided by the charging system. Elements for detecting the receiving coil must be present in the system as well as elements for moving the induction coil, these moving elements being guided by a control device according to the data provided by the detection elements.
These three charging systems, however, have drawbacks which are specific to them and which do not allow them to provide an optimum price/quality ratio.
The first system is certainly economic but not very efficient. It calls for participation from the user which is notably detrimental when the user is a driver of the motor vehicle who may be distracted by this participation, which is to be avoided.
The second system with multiple induction coils is costly. In addition, this second system does not ensure an optimum electromagnetic coupling between one of the induction coils and the receiving coil carried by the electronic device.
The third system is accurate and ensures a good electromagnetic coupling between the inductive coil of the system and the receiving coil carried by the electronic device. However, it is very expensive and relatively not very robust since it is very complicated to implement, the moving elements of the inductive coil and the elements for detecting the position of the receiving coil being easily able to deteriorate, which may give false indications regarding the location of the receiving coil.
In this third system, the detection elements indeed involve having a receiving area for the electronic device on the system that allows the detection elements to ensure optimum detection. This receiving area is then rendered fragile and may be easily damaged.
The problem at the heart of the present invention is to design an inductive system for charging the battery or batteries of a selection of different portable electronic devices that is easily adaptable to each of the electronic devices by ensuring an alignment of the electronic device with the charging system in order to allow inductive charging while not having the drawbacks of the prior art charging systems.